Implantable infusion devices, which can deliver low levels of therapeutic agents to target locations in patients, have been employed or contemplated for treating a variety of diseases. Such implantable infusion devices are often permanently implanted and may be used to periodically or continuously deliver the therapeutic agent. To ensure continued delivery of the therapeutic agent to the patient over time, reservoirs of such devices need to be replenished. Typically such replenishment is accomplished by inserting a needle though the patient's skin and through a septum covering a port in fluid communication with the reservoir.
Because such a device is implanted and thus not able to be directly seen, care must be taken to ensure that the needle is properly placed into the device before injection. If the needle misses the device and, in particular, misses the drug reservoir in the device, the drugs will be immediately dispensed in the body, having potentially dire consequences for the patient. Moreover, if the needle is not fully placed through the septum and into the drug reservoir, the drug reservoir will not be adequately filled, also having potentially dire consequences for the patient.
Port locator devices have previously been described. Such devices are intended to be placed on the patient's skin adjacent the implanted infusion device. A hole or opening in the port locator is positioned over the reservoir port. A needle may then be inserted through the hole in the port locator, through the patient's skin, and into the reservoir port. However, such port locator devices, even when simplistically designed, are difficult to use.
For example, a physician typically uses one hand to identify by touch the location of the implanted device and steady the orientation of the device and uses the other hand to place the port locator in position relative to the implanted device. Thus the physician has no hand available to insert the refill needle through the port locator and into the reservoir port of the implanted device. While it is possible to perform the refill procedure with such port locator devices, the use of such devices is often awkward and may result in inaccurate needle placement due to the awkwardness.